Improvement in middlings-grinding mills



J. MILLS. Middlings-Grndng Mill `N-o. 215,236. Patented May I3, 1879.

UNITED: STATES' PATENT GFFIGE.

JONATHAN MILLS, OF MILWAUKEE, WISCONSIN.

IMPROVEMENT IN MIDDLINGS-GRINDING MILLS.

Specification forming part of Letters Patent No. 215,236, dated May 13, 1879; application filed January 8, 1879.

To all whom it may concern:

Be it known that I, JONATHAN MILLS, of Milwaukee, in the county of Milwaukee and State oi' Wisconsin, have invented certain newV and useful Improvements in Grinding-Mills 5 and I do hereby declare that the following is a full, clear, and exact description of the invention, which will enable others skilled in the art to which it pertains to make and use the same,

'reference being had to the accompanyingdrawings, and to the letters of reference marked thereon, which form a part of this specification.

This invention relates to that class of mills in which the runner-stone is rigidly secured to a vertical drivingspindle, and particularly those mills represented in an application recently tiled in my own name in which the spin-- dle has both ends mounted in an adjustable yoke.

The present invention consists in making the bearings adjustable in the yoke, in the special construction and arrangement of the yoke and bearings and the adjusting devices, and in details of minor importance, all as hereinafter described.

Figure l represents a vertical central crosssection through my mill; Fig. 2,'a horizontal cross-section ofthe same on the line a: x.

A represents a base-plate, sustaining three pillars, B, which in turn sustain the horizontal plate C. The plates and pillars are united by means of bolts or rods D, which are continued upward above the plate C to receive a third horizontal plate, E, and nuts a b, for supporting and adjusting the same. F represents the yoke or frame, in which the two ends oi the spindle are mounted, this yoke being made with an enlarged open center to admit the driving -pulley H, and with two contracted central ends or journals, c d, which serve to maintain the yoke in position, and also to receive and sustain the two ends of the spindle I.

As in my original mill, the yoke has its upper end mounted in the plate O, and its lower end threaded and seated in a nut, J, which is in turn threaded on its exterior and screwed into the base-plate, the two threads being of different pitches, so that the rotation of the nut will raise or lower the yoke.

The spindle is made with two tapered or conical necks, e and f, to form the wearingsurfaces, both necks being tapered downward, as shown. These tapered necks, instead of being seated directly in the yoke, are mounted in two adjustable bearings, g and h, which are secured in the respective ends of the yoke. Ihe lower bearing, g, is closed at the bottom to form an oil-cup, and provided witha vertical screw, i, upon which the spindle is seated, and by which it is sustained, so that it may be lowered within the bearing to compensate for wear. The bearing g has the main portion of its body made cylindrical, and fitted accurately and closely within the nut, and has its lower end threaded into the bearing, as shown in Fig. 1, so that by turning the bearing it may be raised or lowered in the nut to determine the height of the spindle and stone.

The upper bearing, h, is provided with circumferential grooves or teeth, and the yoke provided with a segmental lever pinion, k, which engages with the bearing, as shown in Fig. 1, so that by moving the lever` the bearing may be raised to compensate for the wear of the conical neck, and thus keep the spindle tight and true.

As a means of clamping the two bearings g and h, the ends or necks of the yoke are split or divided on one side, as shown at Z, and provided with transverse bolts or screws m, by which the yokes may be drawn tightly together upon the bearings.

The neckc of the frame may be, and ordinarily is, made to tit upon the box-bearing h with such closeness as to hold it from descending, but at the same time permit its adjustment by the pinion-lever without requiringthe screw 'm to be adjusted.

The upper one of these bolts also serves as a pivot for the pinion-lever. Asa means of operating the nut J, by which the yoke is raised and lowered, it is enlarged at the top and toothed on the periphery, as shown at n; and in the frame there is mounted an upright shaft, o, the lower end of which is provided with a pinion, p, and the upper end with a hand-wheel, r, as shown.

The shaft o will bear in agr'oove or pass through eyes on the side of theV yoke, to pre vent the same from rotating, the form of the present yoke being such that it admits of the driving-belt being applied in nearly all directions.

The lower grinding-stone, K, is secured rigidly to the upper end of the spindle, and the upper stone secured rigidly to the under side of the plate.

The rotation of the hand-wheel turns the nut J, and causes the spindle, its bearings, and the lower stone to move vertically together, so as to change the distance between the faces of the stones. The rotation of the screw t' raises or lowers the spindle within the bearing g, to maintain the proper closeness of fit therein, and the rotation of the bearing g within the nut J raises or lowers the bearing, to compensate for the adjustment of the screw t', and thereby prevent the spindle from being moved vertically in the yoke. The movement of the bearing h compensates for the wear of the upper end of the spindle without changing its adjustlnent.

In order to prevent the spindle from working upward, as it would have a tendency' to do on account of the conical bearings, the drivin g-pulley is adj usted to bear at its top against the upper spindle-bearing, as shown.

Having thus described my invention, what I claim is 1. In a grinding-mill, the combination of the adjustable yoke F, the spindle having the two conical necks, and the two bearings adjustahly mounted within the yoke.

2. In combination with the yoke F and the justable within the bearing, in combination with means of adjustment substantially such as shown, whereby the three independent adjustments are permitted, as described.

5. The combination of thc mill-spindle having the two conical necks, the driving-pulley having a bearing at or against its upper side, the two adjustable spindlebearings g h, and means, substantially such as described, for adjusting said bearings vertically.

In testimony that I claim the foregoing as my own I affix my signature in presence of two witnesses.

JONATHAN MILLS.

Witnesses:

FRANK J. STERN, JNO. H. STEINWAY. 

